# str = "111"
# print(str[::-1])

# str1 = "Hello World"
# str2 = "Hello World"
# str3 = "Hello World"
# print('{0}---{1}---{2}'.format(1,2,3))

# word = 'o'
# string = 'Python'
# result = string.find(word)
# print(result)

string = 'He said, "you have to go forward, ' \
         'Then turn left, Then go forward, and Then turn right."'
# 指定替换两次
new_string = string.replace("Then", "then", 2)
print(new_string)
